Hackers trick Tibetan activists into visiting exploit pages by baiting them with a legitimate report from AlienVault

Hackers are using a recent report about cyberthreats to Tibetan activists as a lure in a new attack against pro-Tibet organizations that distributes Windows and Mac malware, researchers from security vendor AlienVault said on Monday.

The rogue emails seen in those attacks distributed a booby-trapped Word document that exploited a Microsoft Office vulnerability (designated CVE-2010-3333) to install a variant of Gh0st RAT, a remote access computer Trojan.

AlienVault researchers believe that the Tibet attack campaign was organized by the same group of Chinese hackers that launched the so-called Nitro attacks against dozens of chemical sector companies last year.

However, it seems that even though the cyberespionage operation was exposed, hackers haven't given up on targeting pro-Tibet organizations. In fact, they started using AlienVault's report about the campaign as a lure in new attacks against Tibetan activists, said AlienVault researcher Jaime Blasco in a blog post on Monday.

Newly intercepted rogue emails that use spoofed headers to appear as originating from AlienVault warn recipients that Tibetan activist organizations have been targeted in recent cyberattacks.

The emails contain a "more information" link that leads visitors to a Web page displaying a copy of AlienVault's March 13 report. However, hidden JavaScript code present on the page launches exploits a known Java vulnerability (CVE-2011-3544) in the background, Blasco said.

Successful exploitation attempts result in computer backdoors being installed on both Windows and Mac OS X systems. The Mac backdoor had a zero detection rate on VirusTotal when scanned by AlienVault on Monday, Blasco said. Now, it is detected by six out of the 43 antivirus engines used by the service.

The Mac piece of malware connects to a command and control server hosted on a domain name that was associated in the past with attacks involving the Protux backdoor, Blasco said.

It's not clear whether the Nitro gang is responsible for the new attacks against Tibetan activists, but the group is known to have used similar techniques before. In December 2011, Symantec reported a series of malicious emails sent by the Nitro gang that used the company's original report about the group's operations as a lure.

CVE-2011-3544 exploits have been observed in many targeted attacks during the past month. Last Friday, Kaspersky Lab reported the same vulnerability being exploited in an attack against visitors to popular Russian news websites.

Microsoft also reported a spike in the usage of CVE-2011-3544 exploits, even though they have not been incorporated in popular drive-by download toolkits like Blackhole or Phoenix yet. Users are advised to update their Java installations and remove older versions from their systems in order to thwart attacks that leverage this vulnerability, Microsoft researchers said in a blog post on Tuesday.